February 2013 - Devel - libvirt List Archives

[libvirt] [Sheepdog][Libvirt]Test boot VMs from sheepdog volumes in Libvirt
by harryxiyou 02 Feb '13

02 Feb '13

Hi all, We can get "Boot VMs from sheepdog volumes in Libvirt" way from https://github.com/collie/sheepdog/wiki/Libvirt like following. a, prepare a file containing an XML domain description $ cat > sheepdog.xml <domain type='qemu'> <name>testvm</name> <memory>1048576</memory> <os> <type arch='x86_64'>hvm</type> </os> <devices> <disk type='network'> <source protocol="sheepdog" name="testvdi"/> <target dev='hda' bus='ide'/> </disk> <graphics type='vnc' port='-1' autoport='yes'/> </devices> </domain> b, boot from testvdi with virsh $ virsh create sheepdog.xml c, connect to a VNC console of the running VM $ vncviewer localhost I have some following questions about up three steps. 1, Before a or b(up boot step) step, should we have to install our OS into 'testvdi'? That is to say, we have to install OS from os.iso file into 'testvdi', which should use 'qemu-system-x86_64' command to install OS, right? 2, Before this test, shoul we have to build Sheepdog, QEMU, Libvirt environment? 3, This is the storage online management in Libvirt, right? 4, This test just test the codes Morita take a patch named "add network disk support" for Libvirt, which is located here: http://libvirt.org/git/?p=libvirt.git;a=commit;h=036ad5052b43fe9f0d197e89fd… and also test Sheepdog driver for QEMU, right? 5, If i installed a 32bits OS to testvdi, should i modify <os> <type arch='x86_64'>hvm</type> </os> to be <os> <type arch='x86'>hvm</type> </os> , right? 6, The step c (up boot step), which is $ vncviewer localhost Actually, i am not clear about this 'localhost'. Why should we link localhost but other ip addresses? Could anyone please give me some suggestions? Thanks in advance ;-) -- Thanks Harry Wei

2 4

[libvirt] [PATCH] docs: don't ignore virEvent API
by Eric Blake 02 Feb '13

02 Feb '13

Commit 6094ad7b (0.9.3 release) promoted several functions from internal to public, but forgot to fix the documentation generator to provide details about those functions. For an example of what this fixes, look at: file:///path/to/libvirt/docs/html/libvirt-libvirt.html#virEventAddHandle before and after the patch. * docs/apibuild.py (ignored_functions): Don't ignore functions that were turned into official API. * src/util/virevent.c: Fix comments to pass through parser. --- In response to my concerns raised on one of Claudio's patches: https://www.redhat.com/archives/libvir-list/2013-February/msg00048.html docs/apibuild.py | 6 ----- src/util/virevent.c | 78 +++++++++++++++++++++++++++++++++++------------------ 2 files changed, 52 insertions(+), 32 deletions(-) diff --git a/docs/apibuild.py b/docs/apibuild.py index e5cbbe8..2bdbf2d 100755 --- a/docs/apibuild.py +++ b/docs/apibuild.py @@ -64,12 +64,6 @@ ignored_functions = { "virDomainMigratePrepareTunnel3": "private function for tunnelled migration", "virDrvSupportsFeature": "private function for remote access", "DllMain": "specific function for Win32", - "virEventAddHandle": "internal function in virevent.c", - "virEventUpdateHandle": "internal function in virevent.c", - "virEventRemoveHandle": "internal function in virevent.c", - "virEventAddTimeout": "internal function in virevent.c", - "virEventUpdateTimeout": "internal function in virevent.c", - "virEventRemoveTimeout": "internal function in virevent.c", "virTypedParameterArrayValidate": "internal function in virtypedparam.c", "virTypedParameterAssign": "internal function in virtypedparam.c", "virTypedParameterAssignFromStr": "internal function in virtypedparam.c", diff --git a/src/util/virevent.c b/src/util/virevent.c index 6900011..886cb6d 100644 --- a/src/util/virevent.c +++ b/src/util/virevent.c @@ -1,7 +1,7 @@ /* * virevent.c: event loop for monitoring file handles * - * Copyright (C) 2007, 2011 Red Hat, Inc. + * Copyright (C) 2007, 2011, 2013 Red Hat, Inc. * Copyright (C) 2007 Daniel P. Berrange * * This library is free software; you can redistribute it and/or @@ -38,20 +38,25 @@ static virEventUpdateTimeoutFunc updateTimeoutImpl = NULL; static virEventRemoveTimeoutFunc removeTimeoutImpl = NULL; /** - * virEventAddHandle: register a callback for monitoring file handle events + * virEventAddHandle: * * @fd: file handle to monitor for events * @events: bitset of events to watch from virEventHandleType constants * @cb: callback to invoke when an event occurs * @opaque: user data to pass to callback + * @ff: callback to free opaque when handle is removed * - * returns -1 if the file handle cannot be registered, 0 upon success + * Register a callback for monitoring file handle events. + * + * Returns -1 if the file handle cannot be registered, 0 upon success */ -int virEventAddHandle(int fd, - int events, - virEventHandleCallback cb, - void *opaque, - virFreeCallback ff) { +int +virEventAddHandle(int fd, + int events, + virEventHandleCallback cb, + void *opaque, + virFreeCallback ff) +{ if (!addHandleImpl) return -1; @@ -59,25 +64,33 @@ int virEventAddHandle(int fd, } /** - * virEventUpdateHandle: change event set for a monitored file handle + * virEventUpdateHandle: * * @watch: watch whose file handle to update * @events: bitset of events to watch from virEventHandleType constants * + * Change event set for a monitored file handle. + * * Will not fail if fd exists */ -void virEventUpdateHandle(int watch, int events) { +void +virEventUpdateHandle(int watch, int events) +{ updateHandleImpl(watch, events); } /** - * virEventRemoveHandle: unregister a callback from a file handle + * virEventRemoveHandle: * * @watch: watch whose file handle to remove * - * returns -1 if the file handle was not registered, 0 upon success + * Unregister a callback from a file handle. + * + * Returns -1 if the file handle was not registered, 0 upon success. */ -int virEventRemoveHandle(int watch) { +int +virEventRemoveHandle(int watch) +{ if (!removeHandleImpl) return -1; @@ -85,22 +98,27 @@ int virEventRemoveHandle(int watch) { } /** - * virEventAddTimeout: register a callback for a timer event + * virEventAddTimeout: * * @timeout: time between events in milliseconds * @cb: callback to invoke when an event occurs * @opaque: user data to pass to callback + * @ff: callback to free opaque when timeout is removed + * + * Register a callback for a timer event. * * Setting timeout to -1 will disable the timer. Setting the timeout * to zero will cause it to fire on every event loop iteration. * - * returns -1 if the timer cannot be registered, a positive - * integer timer id upon success + * Returns -1 if the timer cannot be registered, a positive + * integer timer id upon success. */ -int virEventAddTimeout(int timeout, - virEventTimeoutCallback cb, - void *opaque, - virFreeCallback ff) { +int +virEventAddTimeout(int timeout, + virEventTimeoutCallback cb, + void *opaque, + virFreeCallback ff) +{ if (!addTimeoutImpl) return -1; @@ -108,28 +126,36 @@ int virEventAddTimeout(int timeout, } /** - * virEventUpdateTimeoutImpl: change frequency for a timer + * virEventUpdateTimeout: * * @timer: timer id to change - * @frequency: time between events in milliseconds + * @timeout: time between events in milliseconds + * + * Change frequency for a timer. * * Setting frequency to -1 will disable the timer. Setting the frequency * to zero will cause it to fire on every event loop iteration. * * Will not fail if timer exists */ -void virEventUpdateTimeout(int timer, int timeout) { +void +virEventUpdateTimeout(int timer, int timeout) +{ updateTimeoutImpl(timer, timeout); } /** - * virEventRemoveTimeout: unregister a callback for a timer + * virEventRemoveTimeout: * * @timer: the timer id to remove * - * returns -1 if the timer was not registered, 0 upon success + * Unregister a callback for a timer. + * + * Returns -1 if the timer was not registered, 0 upon success. */ -int virEventRemoveTimeout(int timer) { +int +virEventRemoveTimeout(int timer) +{ if (!removeTimeoutImpl) return -1; -- 1.8.1

2 2

[libvirt] [Sheepdog][Libvirt]Boot VMs from sheepdog volumes error
by harryxiyou 01 Feb '13

01 Feb '13

Hi all, I wanna boot VMs from sheepdog volumes so i do according to https://github.com/collie/sheepdog/wiki/Libvirt However, some errors happened to me like following. $ ./virsh create os.xml error：create domain from os.xml failure error：(domain_definition):14: Premature end of data in tag domain line 1 (null) ^ $ cat os.xml <domain type='qemu'> <name>testvm</name> <memory>1048576</memory> <os> <type arch='x86_64'>hvm</type> </os> <devices> <disk type='network'> <source protocol="sheepdog" name="testvdi"/> <target dev='hda' bus='ide'/> </disk> <graphics type='vnc' port='-1' autoport='yes'/> </devices> Could anyone give me some help? Thanks. -- Thanks Harry Wei

2 2

[libvirt] [PATCH] maint: update to latest gnulib
by Eric Blake 01 Feb '13

01 Feb '13

CVE-2013-0242 in glibc's regex() can cause a DoS in any daemon that runs a regex search on user input while in a multibyte locale. I'm not sure how hard it would be to trigger such a setup for libvirtd, but rather than risk things, we can avoid the issue: gnulib has worked around the problem, and by updating to the latest gnulib, we can avoid the bug even on platforms where glibc has yet to be patched. * .gnulib: Update to latest, for various fixes, including regex. * bootstrap: Resync from upstream. --- * .gnulib 61c7b1e...a0b25da (45): > regex: avoid infinite configure test > openpty: fix bug where HAVE_OPENPTY wasn't defined > sys_time: port to Solaris 2.6 > regex: test for buffer overrun > regex: fix buffer overrun in regexp matcher > mountlist: don't consider "devtmpfs" as dummy > futimens-tests, utimens-tests: Depend on gettext. > test-getpeername: fix typo > bootstrap: remove the need for a sorted .gitignore > readlinkat: don't depend on gl_FUNC_OPENAT > statat: new module, split out from fstatat > autoupdate > Fix typo in previous change, by including <unistd.h>. > tests: don't assume fd 99 is closed > Fix ChangeLog typo. > stpncpy: port to OS X 10.8 > In intro, say only latest mingw is tested. > unistd: port to recent mingw > Fix typo in comment. > largefile: port better to Mac OS X 10.5 > doc: clarify -Werror > stdint: fix build with Android's Bionic fox x86 > net_if-tests: port to Solaris 7 + GCC 3.4.6 > net_if-tests: port to older Solaris > system-quote-tests: port to older Solaris > c-xvasprintf etc.: fix link errors on older Solaris > locale: port to Solaris 2.6 and 7 + GNU gettext > autoupdate > stdlib: port to Solaris 2.6 > Fix misspellings of "occurred". > autoupdate > autoupdate > doc: update main copyright year > doc: improve ISO 8601 discussion > doc: avoid small caps > regex: conform to strict C > gnulib-tool: fix incompatibility with autopoint 0.18.2 > autoupdate > fprintftime: bring back and reword fwrite comment > autoupdate > stdio: remove now-unnecessary stdio.c > unicodeio: depend on stdio, not ignore-value > fprintftime: depend on stdio, not ignore-value > stdint-tests: Fix expanded-before-required-warning. * modules/stdint-tests (Depends-on): Use AC_REQUIRE. > fwrite: silence __wur only for older glibc versions .gnulib | 2 +- bootstrap | 44 ++++++++++++++++++++++---------------------- 2 files changed, 23 insertions(+), 23 deletions(-) diff --git a/.gnulib b/.gnulib index 61c7b1e..a0b25da 160000 --- a/.gnulib +++ b/.gnulib @@ -1 +1 @@ -Subproject commit 61c7b1e32e11e9e40b4d59ab888a807620befcd3 +Subproject commit a0b25daf001cb1a0352f329e2b5e1640acc88541 diff --git a/bootstrap b/bootstrap index 012907a..bee7765 100755 --- a/bootstrap +++ b/bootstrap @@ -1,6 +1,6 @@ #! /bin/sh # Print a version string. -scriptversion=2012-12-28.10; # UTC +scriptversion=2013-01-20.16; # UTC # Bootstrap this package from checked-out sources. @@ -306,34 +306,34 @@ if test -n "$checkout_only_file" && test ! -r "$checkout_only_file"; then die "Bootstrapping from a non-checked-out distribution is risky." fi -# Ensure that lines starting with ! sort last, per gitignore conventions -# for whitelisting exceptions after a more generic blacklist pattern. -sort_patterns() { - sort -u "$@" | sed '/^!/ { - H - d - } - $ { - P - x - s/^\n// - }' | sed '/^$/d' +# Strip blank and comment lines to leave significant entries. +gitignore_entries() { + sed '/^#/d; /^$/d' "$@" } -# If $STR is not already on a line by itself in $FILE, insert it, -# sorting the new contents of the file and replacing $FILE with the result. -insert_sorted_if_absent() { +# If $STR is not already on a line by itself in $FILE, insert it at the start. +# Entries are inserted at the start of the ignore list to ensure existing +# entries starting with ! are not overridden. Such entries support +# whitelisting exceptions after a more generic blacklist pattern. +insert_if_absent() { file=$1 str=$2 test -f $file || touch $file - echo "$str" | sort_patterns - $file | cmp -s - $file > /dev/null \ - || { echo "$str" | sort_patterns - $file > $file.bak \ - && mv $file.bak $file; } \ - || die "insert_sorted_if_absent $file $str: failed" + test -r $file || die "Error: failed to read ignore file: $file" + duplicate_entries=$(gitignore_entries $file | sort | uniq -d) + if [ "$duplicate_entries" ] ; then + die "Error: Duplicate entries in $file: " $duplicate_entries + fi + linesold=$(gitignore_entries $file | wc -l) + linesnew=$(echo "$str" | gitignore_entries - $file | sort -u | wc -l) + if [ $linesold != $linesnew ] ; then + { echo "$str" | cat - $file > $file.bak && mv $file.bak $file; } \ + || die "insert_if_absent $file $str: failed" + fi } # Adjust $PATTERN for $VC_IGNORE_FILE and insert it with -# insert_sorted_if_absent. +# insert_if_absent. insert_vc_ignore() { vc_ignore_file="$1" pattern="$2" @@ -344,7 +344,7 @@ insert_vc_ignore() { # .gitignore entry. pattern=$(echo "$pattern" | sed s,^,/,);; esac - insert_sorted_if_absent "$vc_ignore_file" "$pattern" + insert_if_absent "$vc_ignore_file" "$pattern" } # Die if there is no AC_CONFIG_AUX_DIR($build_aux) line in configure.ac. -- 1.8.1

2 2

[libvirt] These patches needed to mount the securityfs in containers.
by Daniel J Walsh 01 Feb '13

01 Feb '13

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Simple patch to make sure /sys/kernel/security is mounted inside the container. Systemd attempts to use/mount this file system if it is not present. One of these days I will figure out how to merge patches. securityfs has to be mounted after /sys... Also want to mount it readonly. (Sent patches to wrong list, originally) -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlEL6yUACgkQrlYvE4MpobOTuwCfWkrq/wiPQKPG4y69fIhjDqqr riQAnis3qdRKzRJIpB4PbPGXTgR3nrKt =D+T5 -----END PGP SIGNATURE-----

2 1

[libvirt] This patch adds the label to lxc-enter-namespace
by Daniel J Walsh 01 Feb '13

01 Feb '13

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 (2nd pass) lxc-enter-namespace allows a process from outside a container to start a process inside a container. One problem with the current code is the process running within the container would run with the label of the process that created it. For example if the admin process is running as unconfined_t and executes the following command # virsh -c lxc:/// lxc-enter-namespace --nolabel dan -- /bin/ps -eZ LABEL PID TTY TIME CMD system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 1 pts/0 00:00:00 systemd system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 3 pts/1 00:00:00 sh system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 24 ? 00:00:00 systemd-journal system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 29 ? 00:00:00 dhclient staff_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 47 ? 00:00:00 ps Note the ps command is running as unconfined_t, After this patch, virsh -c lxc:/// lxc-enter-namespace dan -- /bin/ps -eZ LABEL PID TTY TIME CMD system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 1 pts/0 00:00:00 systemd system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 3 pts/1 00:00:00 sh system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 24 ? 00:00:00 systemd-journal system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 32 ? 00:00:00 dhclient system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 38 ? 00:00:00 ps I also add a --nolabel command to virsh, which can go back to the original behaviour. virsh -c lxc:/// lxc-enter-namespace --nolabel dan -- /bin/ps -eZ LABEL PID TTY TIME CMD system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 1 pts/0 00:00:00 systemd system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 3 pts/1 00:00:00 sh system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 24 ? 00:00:00 systemd-journal system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 32 ? 00:00:00 dhclient staff_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 37 ? 00:00:00 ps Everything seems to be working perfectly now. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlEC320ACgkQrlYvE4MpobPDjwCfTLjGarwDOLA333vE+XVp0Zj2 LYkAn3WGX3h309/kJejbE3uvXnIUCKJV =rwfM -----END PGP SIGNATURE-----

2 2

[libvirt] [PATCH] spec: Fix minor changelog issues
by Jiri Denemark 01 Feb '13

01 Feb '13

When a changelog entry references an RPM macro, % needs to be escaped so that it does not appear expanded in package changelog. Wed Jul 5 2011 is incorrect since Jul 5 was Tuesday. Let's suppose it was a result of incomplete update (Tue -> Wed) and change Jul 5 to Jul 6. --- libvirt.spec.in | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libvirt.spec.in b/libvirt.spec.in index 8df908d..8b2458d 100644 --- a/libvirt.spec.in +++ b/libvirt.spec.in @@ -2309,7 +2309,7 @@ fi * Fri Apr 3 2009 Daniel Veillard <veillard(a)redhat.com> - 0.6.2-1 - release of 0.6.2 -* Fri Mar 4 2009 Daniel Veillard <veillard(a)redhat.com> - 0.6.1-1 +* Fri Mar 6 2009 Daniel Veillard <veillard(a)redhat.com> - 0.6.1-1 - release of 0.6.1 * Sat Jan 31 2009 Daniel Veillard <veillard(a)redhat.com> - 0.6.0-1 @@ -2448,7 +2448,7 @@ fi - it's pkgconfig not pgkconfig ! * Mon Nov 6 2006 Daniel Veillard <veillard(a)redhat.com> 0.1.8-2 -- fixing spec file, added %dist, -devel requires pkgconfig and xen-devel +- fixing spec file, added %%dist, -devel requires pkgconfig and xen-devel - Resolves: rhbz#202320 * Mon Oct 16 2006 Daniel Veillard <veillard(a)redhat.com> 0.1.8-1 -- 1.8.1.2

1 1

[libvirt] [PATCH 0/7] documentation improvements - again
by Claudio Bley 01 Feb '13

01 Feb '13

Hi. The first two patches are aimed at avoiding generation of empty argument description lists, which might happen if a function has no documentation for some argument or its return type. This was happening with virTypedParams* functions (see https://www.redhat.com/archives/libvir-list/2013-January/msg01428.html) Patch #3 is just a small cleanup, since a table is not the right thing to use and it looks better in some circumstances. Patch #4 sports processing of code blocks embedded into comments. Basically, it is similar to markdown syntax, except that you only need to indent your code with 2 spaces. Patch #5 prepares for the later patches being able to distinguish between different <pre> blocks. Patch #6 and #7 are pretty much self explanatory, I guess. Note, that SHJS's license is GPLv3. Claudio Bley (7): docs: don't write out empty info attributes for function arguments docs: only generate function argument info for args with a description docs: use a div instead of a 3 column table for undisclosed notices docs: process code blocks similar to markdown docs: add class "description" to div's containing descriptions docs: define style of code blocks inside descriptions docs: syntax highlight code blocks using SHJS docs/apibuild.py | 8 +- docs/libvirt.css | 8 ++ docs/newapi.xsl | 209 +++++++++++++++++++++++++++++-------------------- docs/page.xsl | 5 +- docs/sh_c.min.js | 1 + docs/sh_emacs.min.css | 1 + docs/sh_main.min.js | 4 + 7 files changed, 148 insertions(+), 88 deletions(-) create mode 100644 docs/sh_c.min.js create mode 100644 docs/sh_emacs.min.css create mode 100644 docs/sh_main.min.js -- 1.7.9.5

2 20

[libvirt] Canonical citation for Libvirt
by Lempereur, Brett 01 Feb '13

01 Feb '13

Hi, Is there a canonical paper I can cite for Libvirt in academic publications? The best I've found so far is Bolt, M., Birkenheuer, G., Niehörster, O., & Brinkmann, A. (2010). Non-Intrusive Virtualization Management using Libvirt. Proceedings of the 2nd Design, Automation, and Test in Europe Conference (DATE'10) (pp. 1-6). Dresden, Germany: IEEE. Retrieved from http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5457142&isnumber=54… A lot of frameworks used in academic work have sort of "standard" citations, people that use the framework tend to cite that paper. The authors get citations, we get cool frameworks, everyone wins. Brett ________________________________ Important Notice: the information in this email and any attachments is for the sole use of the intended recipient(s). If you are not an intended recipient, or a person responsible for delivering it to an intended recipient, you should delete it from your system immediately without disclosing its contents elsewhere and advise the sender by returning the email or by telephoning a number contained in the body of the email. No responsibility is accepted for loss or damage arising from viruses or changes made to this message after it was sent. The views contained in this email are those of the author and not necessarily those of Liverpool John Moores University.

2 1

[libvirt] [Libvirt][Sheepdog]Sheepdog pool/volume storage driver for libvirt problem
by harryxiyou 01 Feb '13

01 Feb '13

Hi Sebastian, Morita and other developers, I have studied Sheepdog pool/volume storage driver for libvirt and i have following questions. Please give me some suggestions. Thanks in advance ;-) 1, In libvirt/src/storage/storage_backend_sheepdog.c, i just find we realized create/delete/resize volume(send these parameters to let libvirtd receive and execute them). I cannot find the operations about snapshot, such as creating/deleting snapshot. I cannot also find the operations about opening/closing cache. 2, In the func create/delete/resize volume, we call func 'virCommandRun(cmd, NULL);' to run these commands, which i think the func send these parameters to daemon libvirtd and libvirtd send these parameters to Sheepdog, then Sheepdog executes them, right? 3, In func "virStorageBackendSheepdogCreateVol", it composes cmd like this "virCommandPtr cmd = virCommandNewArgList(COLLIE, "vdi", "create", vol->name, NULL);" then send create parameters. When Sheepdog receive these parameters, how Sheepdog create this volume? I find Sheepdog create a volume like this. $ qemu-img create sheepdog:Alice 256G 4, What are the essences of func "virStorageBackendSheepdogRefreshPool" and "virStorageBackendSheepdogRefreshVol"? In func "virStorageBackendSheepdogCreateVol", after craete volume operations, we call "virStorageBackendSheepdogRefreshVol". But in func "virStorageBackendSheepdogDeleteVol" and "virStorageBackendSheepdogResizeVol", we do not call "virStorageBackendSheepdogRefreshVol", why? 5, Actually, i am not clear about how QEMU receive these parameters (like create/delete/snapshot, etc) and execute the real jobs? Thanks for anyone's suggestions ;-) -- Thanks Harry Wei

3 8